Add support for distinct jsonArray (pointfreeco#57)

Author: mackoj

Sources/StructuredQueriesCore/SQLite/JSONFunctions.swift

@@ -27,14 +27,16 @@ extension QueryExpression where QueryValue: Codable & QueryBindable & Sendable {
   /// ```
   ///
   /// - Parameters:
+  ///   - isDistinct: An boolean to enable the `DISTINCT` clause to apply to the aggregation.
   ///   - order: An `ORDER BY` clause to apply to the aggregation.
   ///   - filter: A `FILTER` clause to apply to the aggregation.
   /// - Returns: A JSON array aggregate of this expression.
   public func jsonGroupArray(
+    isDistinct: Bool = false,
     order: (some QueryExpression)? = Bool?.none,
     filter: (some QueryExpression<Bool>)? = Bool?.none
   ) -> some QueryExpression<[QueryValue].JSONRepresentation> {
-    AggregateFunction("json_group_array", self, order: order, filter: filter)
+    AggregateFunction("json_group_array", isDistinct: isDistinct, self, order: order, filter: filter)
   }
 }
 
@@ -85,14 +87,16 @@ extension PrimaryKeyedTableDefinition where QueryValue: Codable & Sendable {
   /// }
   ///
   /// - Parameters:
+  ///   - isDistinct: An boolean to enable the `DISTINCT` clause to apply to the aggregation.
   ///   - order: An `ORDER BY` clause to apply to the aggregation.
   ///   - filter: A `FILTER` clause to apply to the aggregation.
   /// - Returns: A JSON array aggregate of this table.
   public func jsonGroupArray(
+    isDistinct: Bool = false,
     order: (some QueryExpression)? = Bool?.none,
     filter: (some QueryExpression<Bool>)? = Bool?.none
   ) -> some QueryExpression<[QueryValue].JSONRepresentation> {
-    AggregateFunction("json_group_array", jsonObject, order: order, filter: filter)
+    AggregateFunction("json_group_array", isDistinct: isDistinct, jsonObject, order: order, filter: filter)
   }
 
   private var jsonObject: some QueryExpression<QueryValue> {

Tests/StructuredQueriesTests/JSONFunctionsTests.swift

@@ -40,6 +40,30 @@ extension SnapshotTests {
       }
     }
 
+    @Test func jsonGroupArrayDisctinct() {
+      assertQuery(
+        Reminder.select {
+          $0.priority.jsonGroupArray(isDistinct: true)
+        }
+      ) {
+        """
+        SELECT json_group_array(DISTINCT "reminders"."priority")
+        FROM "reminders"
+        """
+      } results: {
+        """
+        ┌────────────────┐
+        │ [              │
+        │   [0]: nil,    │
+        │   [1]: .high,  │
+        │   [2]: .low,   │
+        │   [3]: .medium │
+        │ ]              │
+        └────────────────┘
+        """
+      }
+    }
+
     @Test func jsonArrayLength() {
       assertQuery(
         Reminder.select {